stuck on grounding (enphase inverters)

System
System Posts: 2,511 admin
I'm getting ready to submit plans for my 7 kw solar array using enphase micro inverters. searching the forum didn't yield anything that I felt would answer my question. In California, what is required for grounding on a grid tied system? Is the ground size based on the kw produced? Do i need to run a separate ground wire to a grounding rod or is the ground bar in the main service panel adequate? I'm sure this question has been answered somewhere before. If so my apologizes.

Thanks,
Bruce.

Comments

  • raydias
    raydias Solar Expert Posts: 68 ✭✭✭✭
    Re: stuck on grounding (enphase inverters)

    Have you reviewed the wiring diagrams located on the Enphase web site.
    http://www.enphaseenergy.com/support/downloads.cfm

    Design Resource section

    you could also just send them a request to see if they have any information on CA requirements.

    I am also looking at designing a system myself, would you be willing to share the documents you are submitting for permit approval (with personal info redacted)
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: stuck on grounding (enphase inverters)

    Probably will come down to your local building department and what they required... For my home near San Francisco, it was build in 1930's and I had to drive a new 8' ground rod when I redid the service entrance (no ground rod originally). Interestingly, we now have to ground gas lines and hot water lines to cold water/ground rod. In the olden days, we had to isolate the gas lines.

    In my humble opinion, do not drive a separate ground rod just for you system--Tie the ground rod(s) together, then run from the single points to where your ground(s) are needed (single point grounding). This reduces the chances of injecting ground currents into your systems (sticking two ground rods feet or many feet apart can have 1,000's of volts differential across them if there is a nearby lighting strike).

    If you have grounded frames on your solar array a fair distance THROUGH the home to get to ground rod... Then I would drive a second ground rod at the side of the foundation and run the frame ground(s) on the outside of the home directly to the ground rod. Do not bring lightning/frame ground runs into the home. Lighting current wants to move the the outside of the home (not into the middle) so running ground runs outside the home is much safer.

    I did not do that with my home--However, we are not in an area that gets direct ground strikes (historically) of lightning to homes.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset